Cpp oauth2 auth client

pulsar-client-cpp/include/pulsar/Authentication.h

@@ -56,7 +56,7 @@ class PULSAR_PUBLIC Authentication {
    public:
     virtual ~Authentication();
     virtual const std::string getAuthMethodName() const = 0;
-    virtual Result getAuthData(AuthenticationDataPtr& authDataContent) const {
+    virtual Result getAuthData(AuthenticationDataPtr& authDataContent) {
         authDataContent = authData_;
         return ResultOk;
     }
@@ -107,7 +107,7 @@ class PULSAR_PUBLIC AuthTls : public Authentication {
     static AuthenticationPtr create(const std::string& authParamsString);
     static AuthenticationPtr create(const std::string& certificatePath, const std::string& privateKeyPath);
     const std::string getAuthMethodName() const;
-    Result getAuthData(AuthenticationDataPtr& authDataTls) const;
+    Result getAuthData(AuthenticationDataPtr& authDataTls);
 
    private:
     AuthenticationDataPtr authDataTls_;
@@ -144,7 +144,7 @@ class PULSAR_PUBLIC AuthToken : public Authentication {
     static AuthenticationPtr create(const TokenSupplier& tokenSupplier);
 
     const std::string getAuthMethodName() const;
-    Result getAuthData(AuthenticationDataPtr& authDataToken) const;
+    Result getAuthData(AuthenticationDataPtr& authDataToken);
 
    private:
     AuthenticationDataPtr authDataToken_;
@@ -160,12 +160,111 @@ class PULSAR_PUBLIC AuthAthenz : public Authentication {
     static AuthenticationPtr create(ParamMap& params);
     static AuthenticationPtr create(const std::string& authParamsString);
     const std::string getAuthMethodName() const;
-    Result getAuthData(AuthenticationDataPtr& authDataAthenz) const;
+    Result getAuthData(AuthenticationDataPtr& authDataAthenz);
 
    private:
     AuthenticationDataPtr authDataAthenz_;
 };
 
+// OAuth 2.0 token and associated information.
+// currently mainly works for access token
+class Oauth2TokenResult {
+   public:
+    enum
+    {
+        undefined_expiration = -1
+    };
+
+    Oauth2TokenResult();
+    ~Oauth2TokenResult();
+
+    Oauth2TokenResult& setAccessToken(const std::string& accessToken);
+    Oauth2TokenResult& setIdToken(const std::string& idToken);
+    Oauth2TokenResult& setRefreshToken(const std::string& refreshToken);
+    Oauth2TokenResult& setExpiresIn(const int64_t expiresIn);
+
+    const std::string& getAccessToken() const;
+    const std::string& getIdToken() const;
+    const std::string& getRefreshToken() const;
+    int64_t getExpiresIn() const;
+
+   private:
+    // map to json "access_token"
+    std::string accessToken_;
+    // map to json "id_token"
+    std::string idToken_;
+    // map to json "refresh_token"
+    std::string refreshToken_;
+    // map to json "expires_in"
+    int64_t expiresIn_;
+};
+
+typedef std::shared_ptr<Oauth2TokenResult> Oauth2TokenResultPtr;
+
+class Oauth2Flow {
+   public:
+    virtual ~Oauth2Flow();
+
+    /**
+     * Initializes the authorization flow.
+     */
+    virtual void initialize() = 0;
+
+    /**
+     * Acquires an access token from the OAuth 2.0 authorization server.
+     * @return a token result including an access token.
+     */
+    virtual Oauth2TokenResultPtr authenticate() = 0;
+
+    /**
+     * Closes the authorization flow.
+     */
+    virtual void close() = 0;
+
+   protected:
+    Oauth2Flow();
+};
+
+typedef std::shared_ptr<Oauth2Flow> FlowPtr;
+
+class CachedToken {
+   public:
+    ~CachedToken();
+    virtual bool isExpired() = 0;
+    virtual AuthenticationDataPtr getAuthData() = 0;
+
+   protected:
+    CachedToken();
+};
+
+typedef std::shared_ptr<CachedToken> CachedTokenPtr;
+
+/**
+ * Oauth2 based implementation of Pulsar client authentication.
+ * Passed in parameter would be like:
+ * ```
+ *   "type": "client_credentials",
+ *   "issuer_url": "https://accounts.google.com",
+ *   "client_id": "d9ZyX97q1ef8Cr81WHVC4hFQ64vSlDK3",
+ *   "client_secret": "on1uJ...k6F6R",
+ *   "audience": "https://broker.example.com"
+ *  ```
+ */
+class PULSAR_PUBLIC AuthOauth2 : public Authentication {
+   public:
+    AuthOauth2(ParamMap& params);
+    ~AuthOauth2();
+
+    static AuthenticationPtr create(ParamMap& params);
+    static AuthenticationPtr create(const std::string& authParamsString);
+    const std::string getAuthMethodName() const;
+    Result getAuthData(AuthenticationDataPtr& authDataOauth2);
+
+   private:
+    FlowPtr flowPtr_;
+    CachedTokenPtr cachedTokenPtr_;
+};
+
 }  // namespace pulsar
 
 #endif /* PULSAR_AUTHENTICATION_H_ */

pulsar-client-cpp/include/pulsar/ClientConfiguration.h

@@ -43,7 +43,7 @@ class PULSAR_PUBLIC ClientConfiguration {
     /**
      * @return the authentication data
      */
-    const Authentication& getAuth() const;
+    Authentication& getAuth() const;
 
     /**
      * Set timeout on client operations (subscribe, create producer, close, unsubscribe)

pulsar-client-cpp/lib/Authentication.cc

@@ -22,6 +22,7 @@
 #include "auth/AuthTls.h"
 #include "auth/AuthAthenz.h"
 #include "auth/AuthToken.h"
+#include "auth/AuthOauth2.h"
 #include <lib/LogUtils.h>
 
 #include <string>
@@ -125,6 +126,9 @@ AuthenticationPtr tryCreateBuiltinAuth(const std::string& pluginName, ParamMap&
     } else if (boost::iequals(pluginName, ATHENZ_PLUGIN_NAME) ||
                boost::iequals(pluginName, ATHENZ_JAVA_PLUGIN_NAME)) {
         return AuthAthenz::create(paramMap);
+    } else if (boost::iequals(pluginName, OAUTH2_TOKEN_PLUGIN_NAME) ||
+               boost::iequals(pluginName, OAUTH2_TOKEN_JAVA_PLUGIN_NAME)) {
+        return AuthOauth2::create(paramMap);
     } else {
         return AuthenticationPtr();
     }
@@ -139,6 +143,9 @@ AuthenticationPtr tryCreateBuiltinAuth(const std::string& pluginName, const std:
     } else if (boost::iequals(pluginName, ATHENZ_PLUGIN_NAME) ||
                boost::iequals(pluginName, ATHENZ_JAVA_PLUGIN_NAME)) {
         return AuthAthenz::create(authParamsString);
+    } else if (boost::iequals(pluginName, OAUTH2_TOKEN_PLUGIN_NAME) ||
+               boost::iequals(pluginName, OAUTH2_TOKEN_JAVA_PLUGIN_NAME)) {
+        return AuthOauth2::create(authParamsString);
     } else {
         return AuthenticationPtr();
     }

pulsar-client-cpp/lib/ClientConfiguration.cc

@@ -36,7 +36,7 @@ ClientConfiguration& ClientConfiguration::setAuth(const AuthenticationPtr& authe
     return *this;
 }
 
-const Authentication& ClientConfiguration::getAuth() const { return *impl_->authenticationPtr; }
+Authentication& ClientConfiguration::getAuth() const { return *impl_->authenticationPtr; }
 
 const AuthenticationPtr& ClientConfiguration::getAuthPtr() const { return impl_->authenticationPtr; }
 

pulsar-client-cpp/lib/auth/AuthAthenz.cc

@@ -91,7 +91,7 @@ AuthenticationPtr AuthAthenz::create(ParamMap& params) {
 
 const std::string AuthAthenz::getAuthMethodName() const { return "athenz"; }
 
-Result AuthAthenz::getAuthData(AuthenticationDataPtr& authDataContent) const {
+Result AuthAthenz::getAuthData(AuthenticationDataPtr& authDataContent) {
     authDataContent = authDataAthenz_;
     return ResultOk;
 }